Comment deletes now allow for animation

For that, have to grab the index path of every table row being deleted,
something that code added in this commit allows for.
Minor change to LFSContentCollection interface

Rename addObject to insertObject since we are not actually adding to the end of the array in that method.

Also add a method that adds content and authors at the same time to remove the possibility that a client may add those in a wrong order.
Support animated inserts, reloads, and deletes

Also introduce a delegate-based interface for LFSContentCollection.

Deletes and inserts are done in a transactional style with respect to the main content array (updates are accumulated and then applied at once).
Revert to previous method names for some aspects of LFSContentCollection interface
Support paragraph breaks, redirect all table updates through appropriate handler
move twitter support checker into AppDelegate
Move openInTwitterApp to AppDelegate
Load web content in embedded web view so as not to leave the collection
Move OHAttributedLabelDelegate and UIWebViewDelegate stuff into a separate object
Unify link handling between body links and buttons to external profiles in detail view

Now tapping on a remote profile button in detail view (which is usually a Twitter bird) will
open the appropriate native application (Twitter) first, and if that fails, the web browser.

Also change appearance of the right footer button in the detail view with a bitmap right-chevron icon.
Merge pull request #63 from Livefyre/dev

Improved way of handling content inserts/deletes/updates allowing for animation of all actions